Submission #1070270

#TimeUsernameProblemLanguageResultExecution timeMemory
1070270underwaterkillerwhaleFlooding Wall (BOI24_wall)C++17
44 / 100
5090 ms559192 KiB
#include <bits/stdc++.h>
#define ll long long
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define reb(i,m,n) for(int i=(m); i>=(n); i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define pb push_back
#define SZ(v) (int)v.size()
#define ALL(v) v.begin(),v.end()

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now ().time_since_epoch().count());
ll Rand (ll l, ll r) { return uniform_int_distribution<ll> (l, r) (rd); }

const int N = 1e4 + 2;
const int Mod = 1e9 + 7;
const ll INF = 1e18 + 7;
const ll BASE = 137;
const int szBL = 320;

int n, m;
int a[2][N];
int dp[2][2 * N];
int f[N][2 * N];
ll sval[2 * N];

int vals[2 * N] = {0};

inline void add (int &a, int b) {
    a = a + b;
    if (a >= Mod) a-= Mod;
}

void solution () {
    cin >> n;
    rep (i, 1, n) cin >> a[0][i];
    rep (i, 1, n) {
        cin >> a[1][i];
        if (a[1][i] <= a[0][i]) swap(a[1][i], a[0][i]);
        vals[m++] = a[1][i];
        vals[m++] = a[0][i];
    }
    sort (vals, vals + m);
    m = unique(vals, vals + m) - vals;
    rep (i, 1, n)
    rep (k, 0, 1) a[k][i] = lower_bound(vals, vals + m, a[k][i]) - vals + 1;
    dp[0][1] = 1;
    dp[0][1] = 1;

    f[n + 1][1] = 1;
    f[n + 1][1] = 1;

    reb (i, n, 1)
    rep (k, 0, 1) {
        rep (j, 1, m) {
            if (j <= a[k][i]) {
                (f[i][a[k][i]] += f[i + 1][j]) %= Mod;
            }
            else {
                (f[i][j] += f[i + 1][j])%= Mod;
            }
        }
    }
    int res  = 0;
    rep (i, 1, n) {
        rep (k, 0, 1) {
            sval[m + 1] = 0;
            reb (j, m, a[k][i] + 1) {
                sval[j] = (sval[j + 1] + f[i + 1][j]) % Mod;
            }
            rep (j, a[k][i] + 1, m) {
                add(res, 1LL * dp[i&1^1][j] * sval[j] % Mod * (vals[j - 1] - vals[a[k][i] - 1]) % Mod);
            }
            sval[m + 1] = 0;
            reb (j, m, a[k][i] + 1) {
                sval[j] = (sval[j + 1] + dp[i&1^1][j]) % Mod;
            }
            rep (j, a[k][i] + 1, m) {
                add(res, 1LL * f[i + 1][j] * sval[j + 1] % Mod * (vals[j - 1] - vals[a[k][i] - 1]) % Mod);
            }
        }
        rep (j, 1, m) dp[i&1][j] = 0;
        rep (k, 0, 1) {
            rep (j, 1, m) {
                if (j <= a[k][i]) {
                    (dp[i & 1][a[k][i]] += dp[i&1^1][j]) %= Mod;
                }
                else {
                    (dp[i & 1][j] += dp[i&1^1][j]) %= Mod;
                }
            }
        }
    }
    cout << res<<"\n";

}

#define file(name) freopen(name".inp","r",stdin); \
freopen(name".out","w",stdout);
int main () {
//    file("c");
    ios_base :: sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int num_Test = 1;
//    cin >> num_Test;
    while (num_Test--)
        solution();
}
/*
no bug challenge +4
mình có muốn dùng mảng này không?
2 + 8 * 2 - 9
4
1 1 1 1
2 2 2 2
*/

Compilation message (stderr)

Main.cpp: In function 'void solution()':
Main.cpp:78:36: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   78 |                 add(res, 1LL * dp[i&1^1][j] * sval[j] % Mod * (vals[j - 1] - vals[a[k][i] - 1]) % Mod);
      |                                   ~^~
Main.cpp:82:46: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   82 |                 sval[j] = (sval[j + 1] + dp[i&1^1][j]) % Mod;
      |                                             ~^~
Main.cpp:92:48: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   92 |                     (dp[i & 1][a[k][i]] += dp[i&1^1][j]) %= Mod;
      |                                               ~^~
Main.cpp:95:42: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   95 |                     (dp[i & 1][j] += dp[i&1^1][j]) %= Mod;
      |                                         ~^~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...